Replaceable excavator tooth



Dec. 1, 1931. G. E. EDMUNDS 1,834,391

REPLACEABLE EXCAVATOR TOOTH Filed Jan. 29, 1930 2 sheets-Shen 1 fr .Il

I I A /.0 ./l 3 la /2 Y 2 Giel-2n lEdmuizCZS De@ l, 1931. G, E, EDMUNDS 1,834,391

REPLAC EABLE EXCAVATOR TOOTH .Filed Jan. 29, 1930 2 Sheets-Sheet 2 676/222 E dmuz Patented Dec. l, 1931 UNITED sTATl-:s

PATENT ori-ica GLENN n annonce, or ooLUiaiiUs. omo, Assisivon 'ro 'Bonner-raciti? com rm, or commises, onro, .a coaronurron or omo REPLACEABLE EXQAVATOB TOOTH Application med January 29, 1830. vSerial No. 424,869.

This invention relates to teeth for use onexcavating implements, such, for instance, as power operated shovels, ditchers, skimmers, drag lines and cranes, in which, for motives of economy, it is usual to produce the tooth in separately formed point and basemembers, in order that the point member, one side of which in use wears away more rapidly than the other, may be replaced by a new point member. The invention has for an outstanding object to provide an improved forni of connecting structure between the meeting ends of the separately formed point and base members, and particularly a form of connection which, while being very secure in its capacityto withstand stresses, will also be of such simple desi n as to make it very economica'l to pro uce by ordinary foundry practice and to be made from manganese steel or any other alloy steel suitable for the purposes to which the tooth is placed.

It has long been the practice in replace;

able point teeth of this kind, to make them reversible, that is, to permit the point member to be changed in its operative position vupon the base member after a certain degrec of wear has' taken place, in order to present an unworn surface with the end in view of securing longer eii'ective use of such point members. Practice has also proved that it is not a real economy to reverse these point members after the first initial wear has taken place, for the reason that such 'a reversible point member is too dull to be used again until it has been resharpened, either by grinding or forging. Here again, the reversible tooth does not prove to be an eco* nomical factor because the user invariably leaves the point member in use as long as it will dig so that when it is eventually re moved it is practicallyfworn out. In other Words there is not enough stock of metalleft to grind or forge the point member toa sharp edge again. Therefore, the reversible tooth is generally used but once and if it is resharpened and used again it will have lost in length over substantially one half of its digging capacity, so that in reality such a reversible tooth becomes merely a short lived replaceable tooth.

The present invention isbased upon arecog- A nition of the short life of the ordinary reversible tooth and the foremost object thereof is to which will ossess a much longer effective life in connection with excavating apparatus than teeth heretofore designed for this service. The 'design of my improved replace able tooth lends itself toward a much stronger base portion or member as well as a superior tooth or oint member design It is another o ject of the invention to coristruct the tooth so that the base member or shank which supports the replaceable point member comprises practically a solid nose extension and from which has been eliminated the structurally weak wings or jaws which cause so much trouble with the greatn er major-it of reversible teeth. It is another object of t e invention to extend the project- .ing nose at the front end oi the base member under the replaceable point member and ush with the base member, thus making a strong support for the replaceable point.

The greatest wear on any tooth of this kind comes on the nose and the top surfaces of the tooth, so that in the reversible type both sides are equal in order to possess'reversibility. As a result the first lite of the tooth is cut short because such teeth. are designed for reversing and not for long life. This destroys the practicability of such a reversible tooth for the reason that the user will not take time to chan e the teeth as often as they should be ino' er to getextended life from them. In other words, these teeth are worn out after their first application and even when resharpened the are still ine* cient because lthey arev too s ort to pnt hach 'on the bucket lip.

The present invention provides which possesses a veryv eat degree of me chan'ical strength, long life ander hard con-Y ditions of service and yet one which may be readily replaced when desired on the werk ing lip of an excavating device. In ohtainw ing this end the nose of the, replaceable tooth member comprising the present invention is provided with a forwardly disposed angular surface so designed as to be self sharpening roduce 'an improved replaceable tooth while the tooth is being used. Further, this tooth will not only be heavier at its working edge or nose but can be very much longer, which provides for continued use after considerable wear has taken place.

It is a further object of the inventionto provide animproved type of wedge lock between the replaceable point member and the base member, wherein the wedgeconsists of a tapered key which is driven into registering recesses provided in the base and point members to held lsuch latter members in secured relationship and to eifectually prevent their accidental se eration.

With these and ot er objects in view, which will appear as the description roceeds, the invention consists in the nove features of construction, combination of elements and arrangement ofparts hereinafter to be more fully described and pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is atop plan View of thelimproved tooth assembly comprising the present invention,

Figure 2 is a side elevation of the tooth,

illustrating the bucket lip in vertical section.

Figure 3 is a vertical sectional view taken through the tooth` Fi re 4 is a horizontalsectional-view on the p ane indicated by the line 4-4 of Figure 3,

Figure 5 is a transverse vertical sectional view on the line 5-5 of Figure 3,

.Figure 6 is a detail perspective view of the base member of the tooth,

Figure 7 is a similar view of the point member, and

Figure 8 is a detail vertical sectional view o a slightly modified form of the invention.

Similar characters oi reference indicatev corresponding parts throughout the several figures of the drawings.

My improved two-part tooth comprises a body or base member 1 and. the removable or replaceable point member 2. The base member is recessed to form a pair of horizontally extending jaws or shanks 3 and 4, one of which, as for instance the lower, is usually longer than the other. and which jaws are bolted to the bucket lip or side by suitable bolts or other fasteners 5, the forward edge or lip 6 of the bucket fitting snugly in the recess 7 formed between the jaws 3 and 4,

rlhe li engages the forward vertical wall 8 of sai recess, so that thrusts on the tooth are imparted directly to the bucket lip and not through the medium of the bolts thereto.

The base member 1 is provided with a forwardly projecting nose portion 9 at its forward end which portion or extension is of less width than the main body of the base member 1 as shown in Figure 4, to provide lateral bearing surfaces or shoulders 10, which are arranged at an angle with respect Verably use a wedge key 21 which is dri-veil ceives the nose extension 9 and the walls of the pocket are shaped to conform with the walls ofthe extension 9 so that the latter will fit snugly and securely within said pocket. The insertion of the nose extension 9 into the pocket 11 is limited by the engagement of the shoulders or surfaces 10 with corresponding inclined shoulders or surfaces 12 provided on the point member 2, and which surfaces serve to receive the thrusts and stresses imparted from the point member to the base member. 4

The u per portion of the base member l provi ed with a iiat inclined` surface 13 whlch forms a rearwardly extending continuationof the flat upper surface ofA the nose portion 9. The surface 13 terminates at its rear edge in an upwardly directed inclined shoulder 14 and, additionally, the surface 13 includes a transversely extending keyway 15. To the rear of the keyway the surface 13 is formed with a socket 16 which entends into the base member-'1 to a position beyond the rear part of the shoulder 14.

The `outer walls of the point member 2 lie substantially ush with the corresponding walls of the base member l so as to provide for ush adjoining surfaces. The rear portion of the oint member 2 includes an upwardly andP angularly extending integral ledge 17, the lower surface 18 oi which engages with the inclined surface 13 oit the base member and is coextensive with the surface 13. The surface 18 `of the point member carries an integral shoulder lug 19, which is shaped to-be received within the rectangular socket 16 formed in the surface 13. Also, the ledge 17 terminates at its rear end in the bevelled surface or shoulder 2G, which cngages firmly with the inclined lsurface or shoulder 14 of the base member l.

To retain this interitting relationship between the base and point members l into the keyway 15, particularly into engagement with the rear surface 22 of the lug 3.9

`and the opposite wall of the keyway l5. Thelv surface 22 conforms with the angularity ci the ke 21 so that as the latter is driven into its tig t position hrm frictional engagement is provided between the surfaces l() and 12 and also the surfaces 14 and 20 ci the base and point members respectively.- The endsof the key 21 may he turned laterally to produce 'she wings 23, which engage with the ccuntersunk portions of the base member 1 to lie flush with such sides and to prevent the accidental withdrawal oi' the key. By this construction a strong and substantial connection is provided between the separable tooth parts with the end in view of permitting the tooth 'to receive the severe strains and stresses of service without injury or breaking of parts, a feature top of the tooth member in the'direction indicated by the arrow b in Figure 3. Similarly, these thrusts are absorbed also by the shoulder 14.

As shown in Figure 8, I may use in place lof the wedge key 21 a bolt 25- for the pur ose of connectlng in detachable order the ase. and point members together. This construction may be employed in lieu of the key 21 as a constructional variation.

In addition to the connection between the vpoint and base members an outstanding feature of the present'invention resides in the .construction of the point or digging tip of the tooth. This tip instead of coming to a point as is the case in earlier constructions, 1s extended to provide a metal shank of considerable thickness, as indicated at 26, and the shank is also of increased length over previous devices. The u per surface of the shank when viewed in slde elevation is, as shown in Figure 3, of curved or arcuate form, as indicated at- 27, while the lower surface of the shank is substantially flat, as at 28, .and terminates short of the upper surface 27. The surfaces 27 and 28are united by a downwardly and rearwardly inclined front wall 29, which is arranged at an angle of 40 -or 45 degrees to the vertical in order to produce a sharp digging edge at the point of juncture of the walls 27 and 29, which is indicated by the numeral 30. In most digging or excavating operations, the shovel or scoop while moving in a digging path describes an arcuate course of movement in a generally ,upward dlrection and the inclination of the surface 29 is that which would be produced in any event by the wear on the nose portion of the tooth if the surface 29 were in practice formed straight or perpendicular to the horizontal.

By this construction of the digging point of the tooth it will be seen that the operam tion of the tooth will be efficient even if the metal wears practically back to the nose extension 9 and in fact the nose portion may be worn this much before replacement of the point members is necessitated.

To reduce the amount of wear which takes place on the digging tip of the tooth thesurfaces 27 and 28 are provided with longitudinally extending grooves 31 which are formed to receive through welding an extremely cations. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed 1n the appended claims,

in which it is my intention to claim all novelty adherent in my invention as broadly as possible in view of the prior art.

What I claim as new and desire to secure by Letters Patent is:

1. A tooth for excavating implements coml prising separable base and point members, the point member being arranged in advance of thebase member andprovided with side walls arranged for registration with the corresponding walls of the base member, an integral nose extension of less width than the base member formed to project forwardly from the base member for reception within a correspondingly formed pocket provided in y.

the rear portion of the point member, a ledge integrally formed with said point member and receivedv within a recess provided in the.

upper surface of said base member, a lug integrally projecting from the lower surface of said ledge and received within a pocket formed in said base member immediately below but in communication with said recess, and removable securing means for retainin the nose extension on said base member an tive pockets. l l

2. -An excavator tooth comprising base and oint members, said base member terminating at its forward end in an inclinedplanar surface, the ends of said surface terminating in longitudinally o'set inclined shoulders, the forward of said shoulders being provided with a nose extension receivable within a pocket formed in said point member, a ledge member and positioned upon the inclined surface of the base member, a lug extension carried by the under and'rear portion of rsaid ledge and receivable within a pocket provided in said base member, and a locking key positioned in a keyway formed in said base member and arranged for engagement with vsaid lug extension to maintain the rear portion of said 'point member infirm engagement with said oii'set shoulders.

In testimony whereof I aiiix my signature.

GLENN E. EDMUNDS.

1e5 the lug on said point member in their respecl formed upon the rear portion of said point 

